Fluid circuit indicator

ABSTRACT

A device for providing an indication of the condition of a pressurized fluid circuit is disclosed. The device includes means defining a restricted zone and a supply of compressible material positioned in communication with the restricted zone. The restricted zone is provided with aperture means exposing at least a portion of the compressible material for visual inspection. Fluid inlet means are connected with a fluid circuit and operate to admit pressurized fluid to the restricted zone, in consequence of which the compressible material is compressed. The contrasting relaxed and compressed conditions of the compressible material afford visual indications of the condition of the fluid circuit.

United States Patent 1191 Cowan Sept. 10, 1974 FLUID CIRCUIT INDICATOR 3,556,044 1/1971 Egrelsits 116/70 [75] Inventor: Larry C y Cowan, Saunderstown, 3,703,879 11/1972 Hut sing, Jr 116/70 Primary Examiner-Louis J. Capozi [73] A signe Leesona Corporation, Warwick, RI, :Ittorney, Agent, or Firm-Albert P. Davis; Burnett W. 22 Filed: Sept. 15, 1972 [21] Appl. No.: 289,578 [57] ABSTRACT A device for providing an indication of the condition [52] U S Cl 116/70 73/406 of a pressurized fluid circuit is disclosed. The device [51] 19/12 includes means defining a restricted zone and a supply [58] Fieid 4 117 of compressible material positioned in communication 73/388 R 91/1. 1 6 with the restricted zone. The restricted zone is pro- 106 106 vided with aperture means exposing at least a portion of the compressible material for visual inspection. Fluid inlet means are connected with a fluid circuit [56] References Cited and operate to admit pressurized flu1d to the restr1cted UNITED STATES PATENTS zone, in consequence of which the compressible mate- 3,203,229 8/1965 PBYQI 73/406 X rial is compressed The contrasting relaxed com- 3,241,514 3/1966 Gnmland 6/70 pressed conditions of the compressible material afford gig- :6 visual indications of the condition of the fluid circuit. 3:492:968 2/1970 Workman, 116/70 9 Claims, 2 Drawing Figures t i A I 1 E F] -E FLUID CIRCUIT INDICATOR The present invention relates to pressure indicators and relates, more particularly, to a device for providing an indication of the condition of a pressurized fluid circuit.

BACKGROUND OF THE INVENTION Devices for providing an indication of the condition of a pressurized fluid circuit are known in the art. These devices include both electrical units andnonelectrical units. The electrical units may take the form of lights which operate on the pressurized fluid from the circuit and which have appropriate interface elements to translate the fluid pressure signal into an illuminated signal. Non-electrical units commonly include elements having movable pistons operated on fluid from the fluid circuit, the position of the piston being available for visual inspection to thus provide a means by which an operator can derive an indication of the condition of the fluid circuit. Electrical devices of the foregoing types are rather costly in that not only are they expensive to manufacture per se, but they must also include interfacing structure between the electrical device and the fluid source. Non-electrical indicators of the types just alluded to, while normally being less expensive to manufacture than their electrical counterparts, are still deficient in numerous respects. Among these deficiencies are the fact that such devices usually consume substantial amounts of fluid. Additionally, these devices often include a number of moving parts. Further, such devices frequently have high capacitance, thus increasing the total capacitance of the fluid circuit. Moreover, these prior art devices usually are of the on off" type, being totally responsive or non-responsive depending upon their specific operating pressure threshold.

OBJECTS OF THE INVENTION With the foregoing in mind, it is one object of the present invention to provide a device for providing an indication of the condition of the pressurized fluid circuit which is simple in construction and durable and reliable in use.

Another object of the present invention is to provide a device for yielding an indicaton of the condition of a pressurized fluid circuit and which is capable of providing an analog readout. Still another object of the present invention is to provide a device for providing an indication of the condition of a pressurized fluid circuit which includes a minimum number of moving parts, is substantially nonconsumptive and is operable at relatively low fluid pressures.

Other objects of the present invention will, in part, be obvious and will, in part, appear hereinafter.

SUMMARY OF THE INVENTION The present invention includes an element providing a restricted zone in the form of fluid receiving chamber. A supply of a compressible material, such as an elastomeric closed cell foam, is situated in communication with the chamber. A lens overlays the sheet or layer of closed cell foam to secure the edges-of the sheet in position surrounding the chamber. A fluid gap 34 is provided between the lens and the sheet. Upon the introduction of pressurized fluid from the circuit into the chamber the fluid is permitted to flow against the opposite sides of the sheet of compressible material. Due to the fact that the edges of the sheet of compressible material are held securely around the rim of the chamber, the pressurized fluid acts to compress the material toward said margin. The sheet is appropriately slotted and relieved to permit ready compression of the sheet under fluid pressure. Upon such compression the interior of the chamber is exposed thereby providing a direct visual signal of the condition of the fluid circuit.

BRIEF DESCRIPTION OF THE DRAWING For a fuller understanding of the nature and objects of the invention reference should be had to thefollowing detailed description taken in connection with the accompanying drawing wherein:

FIG. 1 is a top plan view of a group of visual indicator devices in accordance with the present invention arranged in a gang on a common panel and indicating the condition at several separate locations within the fluid circuit; and

FIG. 2 is a cross sectional view of one of the indicating devices of FIG. 1 shown in connection with a fluid element, the condition of this element being indicated by the device.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring firstly to FIG. 1 of the drawing a mounting panel 10 is illustrated. A plurality of indicatordevices l2a-d which are operable to indicate the condition at various points in a fluid circuit are arranged on panel 10. As seen in this view indicators 12a and are in the closed or non-operative condition indicating that fluid pressure is not present at the points in the circuit to which they are connected. In contrast, indicators 12b and 12d are shown in the open or operative condition, indicative of the fact that fluid pressure is present at the points in the fluid circuit at which they are connected. Therefore, by visual inspection of the indicators in block 10 ready diagnosis of the condition of the fluid circuit may be obtained by an inspector and, in the event of a malfunction in the circuit, the location of the malfunction can be readily traced with the aid of the indicators.

In FIG. 2 a cross section of one of the indicators of FIG. 1 is illustrated. It will be appreciated that the remaining indicators of FIG. 1 will be of the same construction as the one aboutto be described in detail. Thus, the indicator 12 includes a body 20 which, if several indicators are to be ganged or arrayed as shown in FIG. 1, may be a block common to all of the indicators so ganged or arrayed. The body 20 is countersunk to provide a chamber 22 which is disposed centrally in the indicator. A fluid inlet 24 is bored through the base of the chamber 22 and opens outwardly through the base of block 20. The perimeter of chamber 22 is provided with an elevated lip 26 forming a complete margin around the chamber. A sheet or layer of elastomeric closed cell foam material 28, which may be of either plastic or rubber, for example, is positioned to overlay chamber 22 and extend outwardly-therebeyond for a distance. In fact, if the indicators are to be ganged as shown in FIG. 1, a single sheet'28 of closed cell foam material may be employed to accommodate all of the indicators so ganged. A clear flat lens 30 of glass, plas tic or other transparent material overlays sheet 28 and isfastened to block by means of screws 32. By this means the sheet of closed cell foam material is sandwiched between lens and lip 26 to thereby provide a firm grip on the foam material 28 and form a fluid seal between said lens and said lip. In view of the fact that the closed cell foam material is unsupported in the reach directly over chamber 22 an air gap 34 will be provided in this zone. As best seen in FIG. 1 the closed cell foam material 28 is provided with a plurality of slits 36 and relief ports 38. As will be explained in further detail hereinafter the slits 36 and relief ports 38 provide clearances which contribute to prompt compression of sheet 28 when pressure is applied in chamber 22.

With continuing reference to FIG. 2, and for purposes of illustration herein, the fluid circuit may be considered to include a spring return, air actuated cylinder 40 containing a piston 42. Air is supplied from a suitable source under pressure P, through line 44 to cylinder 40. A tee 46 is present in the circuit to conduct the pressurized air to cylinder 40. A further air line 48 is connected with tee 46 and is operable to deliver the pressurized air into chamber 22 via inlet 24. By any type of conventional air control unit 50 the supply air is delivered to air cylinder 40 to extend piston 42. By virtue of the fact that line 48 is connected in the circuit the air to cylinder40 simultaneously is delivered to chamber 22. In consequence thereof the pressurized air is applied both to the lower and upper surfaces of sheet 28, the air passing through slits 36 and relief ports 38 and into air passage 34 to-be applied to both faces of the sheet in-its zone adjacent chamber 22. As a result the closed cell foam material compresses and is drawn toward lips 26. Such retraction of the material is promoted by the clearances afforded by slits 36 and relief ports 38. Accordingly, an inspector viewing this specific indicatorwould note the enlarged opening provided into chamber 22 by virtue of the retraction of sheet 28 of closed cell foam material. To further promote easy reading of the visual indication the interior S2 of chamber 22 may be coated with a highly reflective material such as a paint contrasting in color with sheet 28. The presence of such an expanded oening is, of course, indicative of the fact'that air is being applied to cylinder 22 and consequently that piston 42 is in its extended position. On the other hand, when the pressurized air is closed off from cylinder 40 by the aforementioned control means the pressurized air in the circuit is vented to atmosphere through control unit 50 and the closed cell foam material relaxes to substantially enclose the opening at the top of chamber 22. This indication, of course, discloses to the inspector that the air has been shut off from cylinder 40 and that the piston 42 has been retracted into cylinder 40.

A further advantage of the present invention resides in the fact that if the full level of air pressure required for extending piston 42 is impeded for some reason sheet 28 will not be in its full open position. Rather, the sheet will compress to a degree correlated with the amount of air admitted into chamber 22 and against the opposing surfaces of sheet 28. By reason of this, an analog signal is provided having direct correspondence to the pressure existing in the fluid circuit and thereby providing a readout proportional to the air in the circuit at the point therein being diagnosed.

From the foregoing it will be seen that the present invention provides a new and novel device for indicating the condition of a pressurized fluid circuit which utilizes low air pressure, which provides an analog output signal and which is operable under relatively low fluid pressures. The device also involves no moving parts and does not consume any appreciable amount of the fluid in the circuit.

Certain changes may be made in the apparatus disclosed herein without departing from the scope of the invention. Therefore, it is intended that all matter contained in the above description and shown in the accompanying drawing shall be interpreted as illustrative only and not in a limiting sense.

What is claimed is:

1. A device for providing an indication of the conditions of a pressurized fluid circuit comprising, means defining a closed fluid receiving chamber, a body of compressible material positioned in said chamber defining therein an aperture, means in said chamber exposing at least a portion of said compressible material about said aperture for visual inspection, and fluid inlet means connected with said chamber operable to selectively admit pressurized fluid to said chamber of a pressure sufficient to compress said compressible material thereby to change the dimensions of said aperture and provide a visual indication of the pressure of said fluid.

2. A device as set forth in claim 1 including a housing having said chamber therein, and means about the periphery of said chamber holding said body of compressible material in a fluid tight seal to retain said fluid within said chamber.

3. A device as set forth in claim 2 wherein said aperture is positioned to expand outwardly toward said seal.

- 4. A device as set forth in claim 3 wherein said means visibly exposing the material comprises lens means.

5. A device as set forth in claim 2 wherein said means about the periphery of said chamber comprises a lip around said aperture, and said compressible material is formed as a sheet substantially enclosing said aperture, and said means exposing the material comprises lens means overlaying said sheet and securing it on said lip.

6. A device as set forth in claim 1 including an indicator surface formed in the interior of said chamber of contrasting appearance to said material and visible through said aperture when said dimensions are increased.

7. A device as set forth in claim 5 wherein said sheet is provided with slits comprising said aperture in a position affording displacement of said sheet toward said lip under fluid pressure.

8. A device as set forth in claim 5 including a fluid gap between said sheet and said lens means for admission of pressurized fluid received from said chamber.

9. A device as set forth in claim 1 wherein said body comprises an elastomeric closed cell foam material. 

1. A device for providing an indication of the conditions of a pressurized fluid circuit comprising, means defining a closed fluid receiving chamber, a body of compressible material positioned in said chamber defining therein an aperture, means in said chamber exposing at least a portion of said compressible material about said aperture for visual inspection, and fluid inlet means connected with said chamber operable to selectively admit pressurized fluid to said chamber of a pressure sufficient to compress said compressible material thereby to change the dimensions of said aperture and provide a visual indication of the pressure of said fluid.
 2. A device as set forth in claim 1 including a housing having said chamber therein, and means about the periphery of said chamber holding said body of compressible material in a fluid tight seal to retain said fluid within said chamber.
 3. A device as set forth in claim 2 wherein said aperture is positioned to expand outwardly toward said seal.
 4. A device as set forth in claim 3 wherein said means visibly exposing the material comprises lens means.
 5. A device as set forth in claim 2 wherein said means about the periphery of said chamber comprises a lip around said aperture, and said compressible material is formed as a sheet substantially enclosing said aperture, and said means exposing the material comprises lens means overlaying said sheet and securing it on said lip.
 6. A device as set forth in claim 1 including an indicator surface formed in the interior of said chamber of contrasting appearance to said material and visible through said aperture when said dimensions are increased.
 7. A device as set forth in claim 5 wherein said sheet is provided with slits comprising said aperture in a position affording displacement of said sheet toward said lip under fluid pressure.
 8. A device as set forth in claim 5 including a fluid gap between said sheet and said lens means for admission of pressurized fluid received from said chamber.
 9. A device as set forth in claim 1 wherein said body comprises an elastomeric closed cell foam material. 